THE presence of metallic blue crusts on termite mounds could indicate the presence of other base metals in the surrounding area.
A CSIRO study in the southern Pilbara region of WA, using advances in sample analysis, has shown how the blueish manganese crusts displayed unique zinc signatures that indicated metal deposits were in the vicinity.
The crusts are also found in rock and cave varnishes, making them an easily accessible exploration tool for base metals including nickel and cobalt, which will support the world’s transition to a low emissions future.
Lead scientist Sam Spinks said CSIRO’s innovative new exploration tools and processes were helping to tackle the global challenge of sustainable energy and resources.
“Australian explorers need new, cost-effective techniques to find the next generation of deposits below the surface,” Dr Spinks said.
“As the world transitions to a low emission future, there’s a need for more nickel and cobalt to build electric vehicles and batteries to store renewable energy.
“We’ve shown that analysing zinc isotopes found in manganese crusts have huge potential to be used to explore for these metal deposits, and others.”
CSIRO analysed termite mounds and soils close to a zinc-lead-silver deposit, comparing this data to samples from elsewhere, to prove the connection.
“Zinc is commonly found in most base metal deposits, and over time, it’s released and ends up in a range of natural materials such as soils, termite mounds and vegetation,” Dr Spinks said.
“The zinc is altered as it moves from the metal deposit to the surface, which has traditionally made it unreliable as an exploration tool, but we’ve been able to apply recent advances in data analysis to understand it in more detail.
“This new research shows we can now measure zinc variations, or isotopes, so accurately that we can identify what metal deposit lies deep underground.”
Termite mounds are already being used in Australian exploration, following earlier CSIRO research that found termites bring up small particles from an ore deposit and store them in their mound.
According to CSIRO research group leader Yulia Uvarova, Australian exploration companies had been analysing samples from termite mounds in gold exploration in recent years, and now zinc offered another technique for use in broader environments and to find a range of metals.
